Separate out conda-lock generation into new script

[abejgonzalez]

This makes it easier to regenerate conda lock files without having to run the entire build setup. Instead, users just need to run the generate-conda-lockfile.sh script. This also bounds s3fs to match the version in FireSim (you can now run the FireSim pytests with Chipyard as top packages)

Related PRs / Issues:

Type of change:

• Bug fix
• New feature
• Other enhancement

Impact:

• RTL change
• Software change (RISC-V software)
• Build system change
• Other

Contributor Checklist:

• Did you set main as the base branch?
• Is this PR's title suitable for inclusion in the changelog and have you added a changelog:<topic> label?
• Did you state the type-of-change/impact?
• Did you delete any extraneous prints/debugging code?
• Did you mark the PR with a changelog: label?
• (If applicable) Did you update the conda .conda-lock.yml file if you updated the conda requirements file?
• (If applicable) Did you add documentation for the feature?
• (If applicable) Did you add a test demonstrating the PR?

• (If applicable) Did you mark the PR as Please Backport?

[harrisonliew]

Can the script just generate both the riscv-tools and esp-tools lockfiles instead of requiring you to run twice and change the TOOLCHAIN_TYPE variable?